Palaeogeography and geodynamic evolution of the Gosau Group of the Northern Calcareous Alps (Late Cretaceous, Eastern Alps, Austria)

The sedimentation of the Late Cretaceous Gosau Group of the Northern Calcareous Alps records the complex geodynamic evolution of the northern part of the Austroalpine microplate. The tectonically controlled sedimentation and facies distribution were mainly governed by the oblique subduction of the Pennic-Ligurian ocean below the Austroalpine margin. Most of the Gosau successions comprise two distinct sedimentary complexes. The Lower Gosau Subgroup (upper Turonian-Campanian) is characterized by terrestrial to shallow-marine facies associations: alluvial fan and fan delta deposits, shallow-marine sandstones and sandy limestones, and storm-influenced nearshore and shelf deposits. During the early Santonian sea-level highstand, a great part of the Northern Calcareous Alps was covered by a shallow shelf sea. Palaeotransport directions point to source areas situated both to the north and to the south of the Northern Calcareous Alps.

The Upper Gosau Subgroup (upper Santonian-Eocene) comprises deep-water hemipelagic and turbiditic deposits. Rapid subsidence into bathyal to abyssal depths started diachronously from the northwest (Santonian) to the southeast (Maastrichtian) after a short phase of deformation and erosion. Abyssal deposits in the northern parts of the Northern Calcareus Alps and north-directed palaeotransport indicate a tilting of the slope towards the north. This subsidence pulse is attributed to an event of subcrustal tectonic erosion, probably triggered by the subduction of a topographic high of the South Penninic ocean. The relationships of the Gosau Group of the Austroalpine unit to Late Cretaceous deposits of the Carpathians and Southern Alps are discussed in the framework of a plate tectonic model.     

Quaternary carbonate-rocky talus slope successions (Eastern Alps, Austria): sedimentary facies and facies architecture

Quaternary carbonate-lithic talus slope successions of the Eastern Alps record an overall correlation between prevalent sedimentary facies, depositional geometry, and geomorphic maturity of the slope. After exposure of high cliffs by deglaciation or rocksliding, a low-dipping immature talus dominated by unsorted rockfalls initially accumulates. With progressive talus buildup, slope segments of different dips develop. Concomitantly, prevalent depositional processes change to grain flows and sorted rockfalls in the proximal, steep-dipping (35°–30°) slope segment, while deposits of cohesive debris-flows, ephemeral fluid flows and larger rockfalls prevail in the distal, lower-dipping slope segment. In mature talus deposystems, the proximal slope succession overlies the lower-dipping package of the distal slope along a thin ‘downlap interval’. Immediately after cliff exposure by deglaciation or rocksliding, talus may aggrade at rates of up to a few tens of meters per 1,000 years, but the accumulation rate slows strongly with progressive maturity of slopes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Clone identification and clinal allozyme variation in populations ofAbies alba from the Eastern Alps (Austria)

Allelic frequencies at the polymorphic enzyme loci IDH-1, IDH-2, LAP-1, and 6-PGDH-1 were determined in population samples ofAbies alba from 5 different areas in Austria. The results reveal clear genetic differentiation between the eastern and the western provenances. Gradual frequency clines are observed with all four loci. The amount of variation, measured as average heterozygosity and genotypic diversity, is significantly higher in the west. The multilocus genotypes proved to be useful markers for the identification of clones. Functional differences with respect to substrate specifity were found for the two allozymes coded by the coexisting alleles of the IDH-2 locus.     

Anthracoporella mounds in the Late Carboniferous Auernig Group,Carnic Alps (Austria)

Summary A heretofore undocumented example of skeletal mounds formed by the dasycladacean algaAnthracoporella spectabilis is described from mixed carbonate-clastic cycles (Auernig cyclothems) of the Late Carboniferous (Gzhelian) Auernig Group of the central Carnic Alps in southern Austria. The massive mound facies forms biostromal reef mounds that are up to several m thick and extend laterally over more than 100 m. The mound facies is developed in the middle of bedded limestones, which are up to 16 m thick. These limestones formed during relative sea-level highstands when clastic influx was near zero. The mound facies is characterized by well developed baffler and binder guilds and does not show any horizontal or vertical zonation. Within the massive mound faciesAnthracoporella is frequently found in growth position forming bafflestones and wackestones composed of abundantAnthracoporella skeletons which toppled in situ or drifted slightly.Anthracoporella grew in such profusion that it dominated the available sea bottom living space, forming ‘algal meadows’ which acted as efficient sediment producers and bafflers. BecauseAnthracoporella could not provide a substantial reef framework, and could not withstand high water turbulence, the biostromal skeletal mounds accumulated in shallow, quiet water below the active wave base in water depths less than 30 m. The massive mound facies is under- and overlain by, and laterally grades into bedded, fossiliferous limestones of the intermound facies, composed mainly of different types of wackestones and packstones. Individual beds containAnthracoporella andArchaeolithophyllum missouriense in growth position, forming “micromounds’. Two stages of mound formation are recognized: (1) the stabilization stage when bioclastic wackestones accumulated, and (2) the skeletal mound stage when the sea-bottom was colonized byAnthracoporella and other members of the baffler and binder guilds, formingAnthracoporella bafflestones and wackestones of the mound facies. A slight drop in sea-level led to the termination of the mound growth and accumulation of organic debris, particularly calcareous algae, fusulinids, crinoids and bryozoans, forming well bedded limestones, which overlie the mound facies     

Influence of canopy opening on the environment and herb layer in a northern hardwoods forest

Single- (33–37 m²) and multi-tree (51–151 m²) gaps were created in an Allegheny Plateau northern hard-woods forest to investigate environmental and herb layer response to canopy opening. After gap creation, noon light on clear summer days was brightest north of opening center. At other times of the day, and when skies were overcast, there was no difference in the light quantity beneath opened and closed canopy. Nor was the distribution of soil moisture or of soil or air temperature greatly affected by gap creation. Species establishment tended to be higher near opening centers; otherwise, there was no pronounced effect of canopy opening on plant cover or species richness during the first four years after gap creation. Biotic responses were not significantly correlated with any environmental factor.     

Middle Triassic basin evolution and stratigraphy in the Carnic Alps (Austria)

Summary A local intraplatform basin developed in the Gartnerkofel-Zielkofel area of the Carnic Alps (southern Carinthia, Austria) during the Middle Triassic (Ladinian). This basin was filled with a transgressive basinal sequence composed of the Uggowitz Formation and overlying Buchenstein Formation. At the northwestern slope of the Gartnerkofel, the platform carbonates of the Schlern Dolomite interfinger with the Buchenstein Formation, causing the formation of two depositional sequences. The Uggowitz Formation consists of the Uggowitz Breccia and the Kühweg Member. Sediments of the Uggowitz Breccia were formed by different types of gravity induced processes. The Kühweg Member is a thin sequence of silt-and fine-grained sandstones which were deposited in a slope to basin margin environment by turbidity currents. The overlying Buchenstein Formation consists of hemipelagic to pelagic limestones of Fassanian age with intercalated pyroclastic rocks (Pietra verde). Nodular limestones were deposited under slow rates of accumulation during a relative sea-level highstand. The uppermost Buchenstein Formation is composed of hemipelagic limestone beds with intercalated graded calcarenites and breccias of platform-derived debris, showing characteristics features of a fore-reef slope of the prograding Schlern Dolomite. Uggowitz Formation and basal Buchenstein Formation are interpreted as a transgressive systems tract, nodular limestones from the middle part of the Buchenstein Formation mark an early highstand systems tract, forereef slope sediments of the upper Buchenstein Formation formed during the beginning regression of a late highstand systems tract, the basal part of the overlying Schlern Dolomite probably reflects a lowstand systems tract. The intercalated bedded limestone facies within the Schlern Dolomite is characterized by large, platform derived blocks, slump structures, breccia beds, graded calcarenites and hemipelagic limestones indicating a forereef slope environent. This intercalated facies belongs to the Buchenstein Formation and interfingers with the Schlern Dolomite. Conodonts from this intercalated slope facies point to Late Fassanian age. Therefore, the two Middle Triassic depositional sequences of the Gartnerkofel area can be correlated with the depositional sequences ‘Ladinian 1’ and ‘Ladinian 2’ of the Dolomites, proposed byDe Zanche et al. (1993). A brief comparison with the basinal sequences of similar age of the karawanken Mountains and the Carnia is presented.     

Late Paleozoic reef mounds of the Carnic Alps (Austria/Italy)

The Late Paleozoic (early Kasimovian-late Artinskian) sedimentary sequence of the Carnic Alps (Austria/Italy) is composed of cyclic, shallow-marine, mixed siliciclastic-carbonate sedimentary rocks. It contains different types of skeletal mounds in different stratigraphic levels. The oldest mounds occur at the base of the Auernig Group, within a transgressive sequence of the basal Meledis Formation. These mounds are small and built by auloporid corals. Algal mounds are developed in the Auernig Formation of the Auernig Group, forming biostromes, and Lower Pseudoschwagerina Limestone of the Rattendorf Group forming biostromes and bioherms. The dominant mound-forming organism of these mounds is the dasycladacean alga Anthracoporella spectabilis. In mounds of the Auernig Formation subordinately the ancestral corallinacean alga Archaeolithophyllum missouriense is present, whereas in mounds of the Lower Pseudoschwagerina Limestone a few calcisponges and phylloid algae occur locally at the base and on top of some Anthracoporella mounds. Mounds of the Auernig Formation formed during relative sea level highstands whereas mounds of the Lower Pseudoschwagerina Limestone formed during transgression. The depositional environment was in the shallow marine, low-turbulence photic zone, just below the active wave base and lacking siliciclastic influx. The algal mounds of the Carnic Alps differ significantly from all other algal mounds in composition, structure, zonation and diagenesis; the formation of the mounds cannot be explained by the model proposed by Wilson (1975). The largest mounds occur in the Trogkofel Limestone, they are composed of Tubiphytes/Archaeolithoporella boundstone, which shows some similarities to the “Tubiphytes thickets” of stage 2 of the massive Capitan reef complex of the Guadalupe Mountains of New Mexico/West Texas.     

Meteoric diagenesis of Quaternary carbonate-rocky talus slope successions (Northern Calcareous Alps,Austria)

In the Northern Calcareous Alps (NCA), meteoric cementation of Quaternary talus slopes was mainly sourced by dissolution of matrix and lithoclasts, by leaching of glacial till, and by groundwaters entered from underneath. Cement precipitation can take place within a few hundreds to a few thousands of years after talus deposition, but later diagenetic changes locally are indicated. Downslope along well-preserved talus successions, a change in prevalent diagenetic pathways is related to prolonged availability of pore waters from the apex to the toe of the slope. Talus slopes contain a significant proportion of carbonate mud probably produced by a combination of physical, chemical, and biological processes. ²³⁴U/²³⁰Th cementation ages of talus successions are scattered over a total range of 5–480 ka. The talus relicts of the NCA thus became cemented at highly different times during the late Quaternary. With the available data, we could not identify a specific palaeoclimatic significance of talus cementation.     

An Alpine immigrant: Phragmoceras Broderip, 1839 from the Silurian of the Carnic Alps (Austria)

A rare occurrence of Phragmoceras imbricatum Barrande is recorded from moderately shallow marine Silurian sequences in the Carnic Alps (Austria). The specimen was collected from a condensed series of nautiloid-bearing wackestones/packstones which are documented as being one of the earliest levels of the Silurian Cephalopod Limestone Biofacies deposited along the North Gondwana margin. The presence of this genus and particular species in the Alpine area, whether as an in situ fauna or as a “stray immigrant”, during a period of global eustatic lowstand, adds new data with regard to the mechanisms of faunal exchange of nectobenthic nautiloid taxa between the Carnic Alps, the Prague Basin, SW Sardinia, Avalonia and Baltica which must have been made possible by currents connecting all five areas. It seems likely that some of the nautiloid taxa appearing in the Prague Basin during the Ludlow may have already been present in the Carnic Alps much earlier in the Silurian; these document early faunal affinities with Baltica. As well as confirming the existence of open migrational seaways between these terranes at a precise stratigraphic interval during the Silurian (lower Homerian: Wenlock), the presence of this species also indicates a prevailing more temperate paleoenvironment in these areas which this element of a usually tropical fauna could tolerate, and provides significant evidence that warm water currents reached the Carnic Alps at this time. In addition due to the bathymetric restrictions of the shells of these particular faunas, exchange by currents could not have taken place over great distances, even considering drifted individuals, and therefore indicates the relatively close positions/connections of various peri-Gondwana Terranes such as the Carnic Alps, SW Sardinia and the Prague Basin to Avalonia and Baltica during this time slice.     

Coral-rudist bioconstructions in the Upper Cretaceous Haidach section (Gosau Group; Northern Calcareous Alps, Austria)

Summary In the area of Haidach (Northern Calcareous Alps, Austria), coral-rudist mounds, rudist biostromes, and bioclastic limestones and marls constitute an Upper Cretaceous shelf succession approximately 100 meters thick. The succession is part of the mixed siliciclasticcarbonate Gosau Group that was deposited at the northern margin of the Austroalpine microplate. In its lower part, the carbonate succession at Haidach comprises two stratal packages that each consists, from bottom to top, of a coral-rudist mound capped by a rudist biostrome which, in turn, is overlain by bioclastic limestones and, locally, marls. The coral-rudist mounds consist mainly of floatstones. The coral assemblage is dominated by Fungiina, Astreoina, Heterocoeniina andAgathelia asperella (stylinina). From the rudists, elevators (Vaccinites spp., radiolitids) and recumbents (Plagioptychus) are present. Calcareous sponges, sclerosponges, and octocorals are subordinate. The elevator rudists commonly are small; they settled on branched corals, coral heads, on rudists, and on biolastic debris. The rudists, in turn, provided settlement sites for corals. Predominantly plocoid and thamnasteroid coral growth forms indicate soft substrata and high sedimentation rates. The mounds were episodically smothered by carbonate mud. Many corals and rudists are coated by thick and diverse encrustations that indicate high nutrient level and/or turbid waters. The coral-rudist mounds are capped byVaccinites biostromes up to 5 m thick. The establishment of these biostromes may result from unfavourable environmental conditions for corals, coupled with the potential of the elevator rudists for effective substrate colonization. TheVaccinites biostromes are locally topped by a thin radiolitid biostrome. The biostromes, in turn, are overlain by bioclastic limestones; these are arranged in stratal packages that were deposited from carbonate sand bodies. Approximately midsection, an interval of marls with abundantPhelopteria is present. These marls were deposited in a quiet lagoonal area where meadows of sea grass or algae, coupled with an elevated nutrient level, triggered the mass occurrence ofPhelopteria. The upper part of the Haidach section consists of stratal packages that each is composed of a rudist biostrome overlain by bioclastic wackestones to packstones with diverse smaller benthic foraminifera and calcareous green algae. The biostromes are either built by radiolitids,Vaccinites, andPleurocora, or consist exclusively of radiolitids (mainlyRadiolites). Both the biostromes and the bioclastic limestones were deposited in a low-energy lagoonal environment that was punctuated by high-energy events.In situ-rudist fabrics typically have a matrix of mudstone to rudistclastic wackestone; other biogens (incl. smaller benthic foraminifera) are absent or very rare. The matrix of rudist fabrics that indicate episodic destruction by high-energy events contain a fossil assemblage similar to the vertically associated bioclastic limestones. Substrata colonized by rudists thus were unfavourable at least for smaller benthic foraminifera. The described succession was deposited on a gently inclined shelf segment, where coral-rudist mounds and hippuritid biostromes were separated by a belt of bioclastic sand bodies from a lagoon with radiolitid biostromes. The mounds document that corals and Late Cretaceous elevator rudists may co-occur in close association. On the scale of the entire succession, however, mainly as a result of the wide ecologic range of the rudists relative to corals, the coral-dominated mounds and the rudist biostromes are vertically separated.     

Distribution and habitat segregation on different spatial scales among diploid, tetraploid and hexaploid cytotypes of Senecio carniolicus (Asteraceae) in the Eastern Alps

MethodsTo evaluate the role of Si in K deficiency-induced inhibition of growth of soybean (Glycine max) seedlings, the effects of K deficiency on shoot and root growth, hydrogen peroxide accumulation, K contents, lipid peroxidation and activities of antioxidant enzymes in the absence and presence of 2 mm sodium silicate (Na₂SiO₃) were investigated.ConclusionsApplication of Si to soybean seedlings grown in K-deficient medium markedly enhanced K use efficiency. Therefore, Si not only increases tolerance to nutrient toxicity, but also ameliorates symptoms associated with deficiency in essential nutrients in plants.     

Tectonically controlled late cretaceous terrestrial to neritic deposition (Northern Calcareous Alps, Tyrol, Austria)

Summary The Turonian to Santonian terrestrial to neritic succession (Lower Gosau Subgroup) in the Northern Calcareous Alps of the eastern part of the Tyrol, Austria, provides an example for deposition on a compartmentalized, narrow, microtidal to low-mesotidal, wave-dominated, mixed siliciclastic-carbonate shelf. The shelf was situated in front of a mainland with a relatively high, articulated relief, and underwent distinct changes in facies architecture mainly as a result of tectonism. The investigated succession was deposited above a deeply incised, articulated truncation surface that formed when the Eo-Alpine orogen, including the area of the future Northern Calcareous Alps, was uplifted and subaerially eroded. Distinct facies associations were deposited from (1) alluvial fans and fan deltas, (2) rivers, (3) siliciclastic lagoonal to freshwater marsh environments, (4) areally/temporally limited carbonate lagoons, (5) transgressive shores, (6) siliciclastic shelf environments, and (7) an aggrading carbonate shelf. During the Turonian to Coniacian, the combination of high rates of both subsidence and sediment accumulation, and a narrow shelf that was compartmentalized with respect to (a) morphology of the substratum, (b) fluviatile input of siliciclastics and contemporaneous input of carbonate clasts from fan deltas, (c) deposition of shallow-water carbonates, and (d) water energy and-depth gave rise to an exceptionally wide spectrum of facies as a distinguishing feature of the succession. With the exception of facies association 7, which formed only once, depositional sequences in the Turonian to Coniacian interval contain all of the facies associations 1 to 6. During Turonian to Coniacian times, the shelf was microtidal to low-mesotidal, and was dominated by waves, storm waves and storm-induced currents. In vegetated marshes, schizohaline to freshwater marl lakes existed. Transgressions occurred onto fan deltas and in association with estuaries, or in association with gravelly to rocky shores. The transgressive successions, including successions deposited from transgressive rocky carbonate shores, are overlain by regressive successions of shelf carbonates or shelf siliciclastics. Deposition of shallow-water carbonates generally occurred within lagoons and over short intervals of time. A „catch-up” succession of shelf carbonates about 100 m thick accumulated only in an area protected from siliciclastic input. In its preserved parts, the Turonian to Coniacian succession does not record deposition adjacent to major active faults. Lateral changes in thickness result mainly from onlap onto the articulated basal truncation surface. Subsidence most probably was controlled by major detachment faults outside the outcrop area, and/or was distributed over a wide area in association with secondary faults above the major detachments. During Coniacian to Early Santonian times, both the older substratum and the overlying Turonian-Coniacian succession were subaerially exposed, faulted and deeply eroded. The following Early Santonian transgression ensued with rocky carbonate shores ahead of a sandy, narrow shoreface-inner shelf environment and a deeper shelf with intermittentlydysaerobic mud. The transgression was associated with the influx of cooler and/or nutrient-rich waters, and heralds an overall deepening. Still during the Early Santonian, the deepening was interrupted by another phase of subaerial exposure. Subsequently, a short phase of shelf deposition was terminated by deepening into bathyal depths.     

Genesis of a soil seed bank on a primary succession in the Central Alps (Ötztal,Austria)

Soil seed bank and standing vegetation were investigated on the Rotmoos Glacier foreland (Ötztal, Tyrol, Austria) along the chronosequence (i.e. on the pioneer, early, and late successional stage) as well as on a subalpine pasture beyond the glacier foreland (old successional stage). We aimed to answer the following questions: (1) How large are soil seed banks along the successional gradient? (2) Do the seed banks reflect the actual standing vegetation or do they remember earlier successional stages or do they represent already the next successional stage?     

The schulterkofel section in the Carnic Alps,Austria: Implications for the carboniferous-permian boundary

Summary The upper part of the LowerPseudoschwagerina Limestone (Rattendorf Group), outcropping on the northwestern flank of Schulterkofel Mountain, Carnic Alps (Austria) is described with special emphasis on fusulinid microfossils and facies. This fusulinid-rich section offers an ideal opportunity for biostratigraphy in defining the Permo-Carboniferous boundary in this region. The LowerPseudoschwagerina Limestone is composed of shallow-marine limestones with intercalated thin siltstone and sandstone beds. Fusulinid limestones are represented by two types of wackestones, both containing large quantities of smaller foraminifers. Fusulinid grainstones are rare. Limestones rich in fusulinids were found only within the bedded limestone facies in beds both below and especially above siliciclastic intercalations. This may indicate that the best living conditions for fusulinids existed immediately before and especially after the climax of a regressive phase (sea-level lowstand). The fusulinid limestones were deposited within a protected, shallow-marine shelf environment with normal salinity. Pseudoschwagerinid fusulinids appear in the upper part of the LowerPseudoschwagerina Limestone, in samples SK 107d (undeterminable species) and SK 108, i.e. between 92 m and 93 m above the base of the section within a bedded limestone immediately above the uppermost clastic intercalation. The fusulinid fauna is represented by about 30 species belonging to only a few genera. Species ofTriticites andRugosofusulina dominate, whereas those ofDaixina, Rugosochusenella andPseudofusulina are rare. A characteristic feature of the fauna is the strong similarity with fusulinid faunas described from Russia as well as from Middle and East Asia. Some of the described fusulinids are new for the Carnic Alps. The first appearance ofPseudoschwagerina andOccidentoschwagerina (Occidentoschwagerina alpina Zone) in the upper part of the LowerPseudoschwagerina Limestone in the Schulterkofel section defines the position of the Carboniferous-Permian boundary.     

The impact of trampling by tourists on a high altitudinal grassland in the Tyrolean Alps,Austria

The long term effect of tourist trampling on a high altitudinal grassland (Caricion curvulae) in the Tyrolean Alps was investigated.Even under slight trampling the frequency of sensitive species decreases. The most sensitive species were found to be fruticose lichens, followed by mosses, some forbs and broadleaved grasses. Tolerant to trampling are the dominant species Carex curvula, and Ligusticum mutellina, which do not disappear completely even at a tourist frequency of 150 tourists per metre per day. Trampling increases soil bulk density moderately but has no marked effect on the soil water content.Comparison with high alpine sedge heath vegetation in North America shows a surprising uniformity of this vegetation type in response to trampling and also indicates that the common generalisation that alpine ecosystems are fragile and sensitive to disturbance does not hold true in this context. Furthermore these results represent evidence against the theory that ecosystems with low diversity are much more sensitive to arteficial impact than ecosystems with high diversity. However, if even the most resistant plants which are the dominant sedges are destroyed completely the rate of recovery is very low and may last for a long time. In the case of Carex curvula this is supported by the fact that it has very low seed production and grows mainly vegetatively. The rate of spread of the rhizome system of this species is 8 mm in 10 years. Similar figures may apply for the sedge species dominating in the alpine vegetation of North America. Thus fragility of this vegetation in regard to trampling does not mean low tolerance but low regeneration.Nomenclature of species follows Ehrendorfer (1973) for vascular plants and Poelt (1974) for lichens.The PCA calculations were done at the Computer laboratory of the University of Wales during a post doctoral stay at the School of Plant Biology in Bangor, U.K. I would like to record my thanks to Prof. Dr. P. Greig-Smith for fruitful discussions and reading the draft.     

Distribution,activity, life-history and standing crop of Julidae (Diplopoda,Myriapoda) in the Central High Alps (Tyrol,Austria)*

The research area includes subalpine meadows, alder communities, dwarf-shrub heaths, lichen heaths and highalpine meadows (1960 m–3090 m a.s.l.). The material consists of 4419 Julidae (31.6% adult) collected by extraction of litter samples (66.4%), in pitfall traps (26.3%) and by handsampling (7.3%). Cylindroiulus meinerti (Verhoeff) only occurred below 2000 m; Leptoiulus saltuvagus (Verhoeff) was mainly found at Alnus viridis sites; Leptoiulus simplex (Verhoeff) had its main distribution in the lichen heath (2200-2300 m); Ommatoiulus sabulosus (L.) was found most frequently in the subalpine meadow and Leptoiulus alemannicus (Verhoeff) occurred up to 2800 m without any altitudinal concentration. Adults of L. saltuvagus showed only one distinct activity peak in September, those of L. simplex were diplochronous (June/September) and O. sabulosus summer stenochronous (July). L. saltuvagus reached maturity in stage IX (only males), X or XI after four or five Years. In their first year of growth the members of a generation reached the third or fourth stage, in the second year the sixth or seventh, in the third year the eighth or ninth. Females could carry full-sized eggs in the autumn of the fourth year in the tenth stage or in the fifth year in stage eleven. Apparently eggs may be laid in spring of the fifth or sixth year. Overwintering density of L saltuvagus in alder litter was found to be 215.6 ± 38.7 inds m^?2, the mean biomass 1.16 g m^?2(max. 1.88 g m^?2). Mean annual production during the growth period of 4-5 months was in the order of 0.85 g m^?2 (max. 1.36 g m^?2).     

Palaeoecology of solitary corals in soft-substrate habitats: the example of Cunnolites (upper Santonian, Eastern Alps)

The upper Santonian Hofergraben Member (Eastern Alps) provides an example of a soft‐substrate habitat suited mainly for solitary corals (Cunnolites), for colonial forms of solitary coral‐like shape (Placosmilia, Diploctenium), and for colonial corals of high sediment resistance (e.g. Actinacis, Pachygyra). The Hofergraben Member consists mainly of silty‐sandy marls of wave‐dominated, low‐energy shore zone to shallow neritic environments. Substrates of soft to firm mud supported level‐bottoms of non‐rudist bivalves, gastropods, solitary corals, colonial corals, rudists, echinoids, and benthic foraminifera. Boring and/or encrustation of fossils overall are scarce. In the marls, Cunnolites is common to abundant. Both a cupolate shape and a lightweight construction of the skeleton aided the coral to keep afloat soft substrata. Cunnolites taphocoenoses are strongly dominated by small specimens (about 1–3 cm in diameter). Cunnolites was immobile and mostly died early in life upon, either, smothering during high‐energy events, rapid sedimentation associated with river plumes, or by toppling and burial induced by burrowing. Comparatively few large survivor specimens may show overgrowth margins interpreted as records of partial mortality from episodic sedimentation or tilting on unstable substrate. Scattered pits and scalloped surfaces on large Cunnolites may have been produced, in some cases at least, by predators (durophagous fish?). Post‐mortem, large Cunnolites provided benthic islands to corals, epifaunal bivalves and bryozoans. In a single documented case of probable in vivo contact of Cunnolites with the colonial coral Actinastraea, the latter prevailed.